Page History

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• Retire aXe
• Retire aXeSIM
  • (currently not functional (web form); probably not a huge effort on top of aXe)
• Leverage the JWST infrastructure
  • just crds, gwcs and asdf?
  • Unclear yet how easy it would be to get HST distortion models for grism into gwcs
    • Distortion is the same as for imaging; trace & dispersion are polynomials (for WFC3)
    • For JWST start in undistorted reference frame for catalog
    • aXe files also include other things like sensitivity
  • stpipe? datamodels? specutils? nddata? specreduce?
• Enable common "Grismconf" infrastructure for:
  • pyLINEAR
  • grizli
  • EM2D, and Nor's other modules
  • JWST pipeline
  • (WFIRST)
• Ensure that users can do all the flavors of geometric transformations (and can understand them)
• Make sure calibration (files) are consistent with the approach to geometry
• Support the following HST modes:
  • WFC3/IR
  • ACS
  • WFC3/UVIS?
• Compatible with JWST pipeline outputs of WFSS modes (NIRISS and NIRCam)

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1. Training – Run the aXe WFC3 Jupyter-notebook Cookbook
2. Refactor grizli | pyLINEAR | Nor's code to use JWST version of grismconf?
   1. refactor HST reference files / geometric distortion info
   2. refactor XXX to use JWST grismconf
   3. compliant gwcs for all code bases 
3. All code bases outputs 1D and 2D in formats compatible with specutils
4. Fork the JWST pipeline as a basis? 
   1. Compare JWST CALWEBB_SPEC2/3 steps to what aXe and grizli, etc are doing.
5. Assess performance issues of grismconf vs. JWST pipeline version?
6. Jupyter notebook illustrating how to do the equivalent aXedrizzle without using aXe?
   • E.g. reproduce cell 7 of the WFC3 aXe cookbook without using Astrodrizzle
     • Possibly first converting WCSs to gWCS to include distortion info?
   • Using reproject package (doesn't yet have drizzle algorithm though)
   • Using JWST pipeline version of drizzle
   • JWST pipeline is doing the co-adds in 1D space 
     • not currently in 2D extractions, but this should be possible with the current code
7. Reproduce steps of aXeprep in a Jupyter notebook using Astropy ecosystem.
   1. There is a prep module in grizli that has a lot of useful functionality that isn't upstream
   2. Look at tools there that could be pushed upstream
      1. e.g. image alignment – not all grism specific
8. Write a summary of science use-cases for each of the grism packages
   1. exists already in roadmap? SSG webpage? WFC3 web pages?
9. Illustrate in a Jupyter notebook how to do a WFC3 forward-model simulation without using aXeSIM
   1. E.g. using grizli or SBE, which might eventually be refactored to use a common grismconf
   2. Or using aXeSIM
   3. Or using specutils + synphot?
      1. Does specutils support the full geometric transformation pipeline that the JWST pipeline does, already, since it supports gwcs?
      2. Does synphot in principle support applying the throughput?
10. Illustrate in a Jupyter notebook how to do flat fielding without using aXe
    1. E.g. using JWST pipeline machinery
11. Illustrate in a Jupyter notebook how to flag contamination without using aXe.

Use-Cases / Workflows

1D spectral extraction for perfectly registered & perfectly calibrated data

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